In a related art, in an image recognition technique, image processing such as smoothing processing of an image, differential processing on images with different degrees of smoothness, minimum value/maximum value extraction (feature point extraction) processing after differential processing, or feature point calculation processing to calculate a light quantity value gradient information or the like near a feature point is performed as basic processing.
Also, as a technique to perform these kinds of processing at high speed, there is a silicon retina chip technique which imitates a retinal neuron of a body. In this technique, pixels formed on a semiconductor substrate are connected to each other through a variable resistance circuit including a metal-oxide-semiconductor field-effect transistor (MOSFET) and smoothing processing between the pixels is performed, at high speed. However, in the above silicon retina chip, while it is possible to increase a speed of smoothing processing, a pixel area where a variable resistance circuit is to be provided is increased in a pixel region of a semiconductor substrate. Thus, there is a case where the number of pixels is decreased compared to that of a normal image sensor.